The Moriarty Glitch
by wicked-n-lazy
Summary: A glitch in time pulls The Doctor and Donna on a detour from their travels, leaving them standing on Baker Street, London. But something's wrong, and it isn't the same Baker Street that either of them are familiar with...
1. Default

AN: I made my way quite recently all the way through Nine up to Ten, and just started Eleven. Doctor Who has drawn me right the way in, and I just had a random little idea for a cross over. However, there are lots of details I haven't worked out yet, so updates may take a while if I manage to get through this story. The last fic I started on a whim kind of fizzled out of me, but I thought I'd give it another go. Will try to preplan a bit more of this one before posting any more, but hope you enjoy it anyway!

I chose Ten and Donna because they are my favourite.

* * *

A journey in the TARDIS was rarely a smooth one; the ship designed for six pilots had for a long time only been directed by one, who was currently running circuits around the control panel as he tried to steady an unusual amount of turbulence.

''I'll smudge my eyeliner in a minute!'' Donna scowled, holding her travel mirror steady on her lap, sticking out a boot so that her make up bag couldn't slide away as the TARDIS tipped.

The Doctor lunged for a set of buttons to his right, perplexed as the ship continued to shake in the vortex.

''Come on, stop being so naughty-'' He muttered to the control panel, glasses glowing blue from the lights that winked at him disobediently. It wasn't playing nice. But it couldn't help it. Something was pulling the TARDIS off their planned route, something small but significant, but he couldn't manage to trace it with all the rocking around. A thin hand flew up to grab at short brown hair, already ruffled in its usual style.

''We're going to have to make a detour, I can't pull us out of this- we're caught in something, like a drain, it's pulling us down-''

''A detour where? What's pulling us down?''

Donna watched her makeup bag shoot across the TARDIS floor. She let it go, mirror still in hand as she stumbled across to the control panel. None of it made any sense to her; she wondered sometimes how much of it actually made sense to The Doctor…

''Oof, _there_ we go, we're out of the slipstream now! I should at least be able to land us…''

''Land us _where_?''

Despite having no clue what had gripped the TARDIS, The Doctor's eyes were alight, grinning across at his red headed companion.

''We're about to find out!''

* * *

''All of time and space and your default is London…'' Donna muttered, retrieving the various contents of her bag from across the TARDIS floor. She shoved them back into the bag along with the mirror and zipped it with relish, tossing it to rest on top of the control panel.

''Nothing wrong with London. Especialllllly- ooh, Baker Street...''

''Yeah, right. _Amazing_…''

''Something yanked us in this direction, I just need to work out why…trying to get a scan running.''

''Right. Well while you get things sorted in here, I'm going to grab a coffee.''

''Ooh, Latte for me,'' The Doctor responded, focused on the TARDIS controls. He could feel _that look_, though, and as he raised his eyes to Donna again he saw the raised eyebrow and the ghost of a smirk on her lips. ''What? _What_?''

With a sigh, Donna Noble stepped out of the TARDIS. The air was unmistakeably _London_,though why she couldn't exactly explain in words_. _It just was, and she knew it all too well, shrugging her jacket around her a little more against a chilly breeze. It was wet out, too. Of course it bloody was. She took a few steps forward towards the main street, casting her eyes up and down the road for the nearest coffee place.

Something niggled in her memory as she did so. She frowned, looking from one end of the street to the other, and back again, trying to pinpoint what it was.

''Wasn't there some museum on this road or something?''

''Actually make it an espresso, think I need a jolt to figure this out. Looks like there was some sort of glitch as we were passing…'' The Doctor called, still fiddling with the controls.

''I swear there was…Doctor, the Sherlock Holmes museum's gone.''

The Doctor suddenly appeared, sticking his head out from around the TARDIS door and looking supremely disappointed.

''Awww, no, I liked it in there, the people all dressed up in character and the old floorboards- have they closed it down?''

''No. It's just….gone. Like it weren't even there…''

She indicated the space, which presented nothing now but a small shop dedicated to the Beatles and a slightly-better-than-grim café and sandwich bar called Speedy's.

''Donna.''

She looked in the direction that the Doctor was staring over his glasses, her gaze settling on the black door of a house. The knocker was askew, the numbers above reading 221B.

''Yeah, so? This is Baker Street, that's the address Sherlock Holmes lived in.''

''Yes, but there _is_ no 221B…there never has been. It was always fictional and now…here it is. And the museum's gone, just gone…oh.''

''What?''

''_Oh_!''

''_What_, spaceman?'' Donna knew this game could go on forever if she didn't snap him out of it sharply.

''That's it,'' The Doctor said, his grin at full elasticity, ''another universe, this is another universe, separate from yours and almost the same except that here, 221B is real, and someone lives there.''

''What, d'you mean- no. _No, _shut up, Sherlock Holmes isn't real, he was made up like a hundred years ago by what's his face.''

''Arthur Conan Doyle, yes. But there was a glitch in time. Something's happened in this universe that wasn't meant to, and the TARDIS was drawn to it…this is where the source is.''

''How can Sherlock Holmes exist in another universe? How?''

''A story has a life of its own- when you create a story, you are literally creating life, creating something out of nothing but words and imagination, and that must create universes where those things are reality…it's just a different reality, Donna, do you see? Every decision you make can spawn a dozen different universes, all focused on the other decisions you could have made, but didn't.''

''Are you telling me that every time someone writes something, it makes another universe?''

''Quite possibly. Well, pretty likely. Welll- yes.''

''So, Sherlock Holmes is up there, right now.''

''Yes.''

''Every story?''

''Yup.''

''So somewhere out there in another universe, there's a real Jack Sparrow that looks like Johnny Depp?''

''Umm-''

''Oh my _God_!''

''Well, he might not look the same, but essentially…oi! Anyway, we need to work out what happened here, what caused the glitch. Donna-'' The Doctor was beaming at her, before looking across the road to the glossy black door, ''let's pay a visit to Sherlock Holmes.''


	2. 221 B

AN- Chapter two, here goes nothing! Thanks to those of you who have read and commented already, you're very kind.

* * *

_Taptaptaptap._

The Doctor knocked the door with great relish, standing back with Donna as they waited for an answer. She frowned, nudging him with her elbow.

''Hold on. If we're about to meet Sherlock Holmes, why aren't we in Victorian times?''

''I don't know. Great isn't it?'' The Doctor continued to grin, rapping the knocker one more time.

''This is like Agatha Christie on another level…oh my God- does that mean-''

The travellers looked at each other, their eyes wide, alighting on the same conclusion.

''Poirot!'' They chorused, caught in the middle of their laughter when the door was opened. An older lady looked at them with a quizzical smile, short, fluffy brown hair greying at the temples. Her eyes were friendly, but curious.

''Sorry, caught me doing the washing up,'' she told them, waving a marigold clad hand, ''can I help you?''

''Yes, actually, we're ah, here to see Sherlock Holmes…'' The Doctor said, shooting Donna a conspiratorial look.

''Oh, umm- do you have an appointment? It's just that I don't think he's interested in seeing visitors just now, he's in a funny mood. Well, he very often is, but funnier than usual…''

''We're from the gas board, actually, here to give everything a check over, there's been a few problems in the area you see.'' Donna replied, elbowing the Doctor. A loud 'of course!' and a nod was his response, whipping out the psychic paper he kept inside his jacket pocket.

''Sorry, it's just not every day you get to meet a famous person doing the rounds.'' He added. ''Just a routine check, nothing to worry about, and we'll be out of your hair before you know it, Mrs-?''

''Oh, Mrs Hudson.'' The woman replied, unable to help smiling back at the bespectacled young man on her doorstep.

''Mrs Hudson, of course- may we come in?''

* * *

''That's a funny little gadget you've got there, dear.'' Mrs Hudson remarked as she handed Donna a cup of tea. There was a steady yet pleasant high pitched humming noise filling the kitchen as the Doctor gently swept the sonic screwdriver around, his tongue tucked into the corner of his mouth in concentration.

''Oh it's the latest tech.'' Donna assured her, watching him work. He veered up and around to the ceiling once, twice, a last time before he shut the screwdriver off.

''There's another kitchen upstairs, yes?'' She asked, setting her tea down. The landlady nodded.

''Yes, that's the boys kitchen.''

''Mind if I scurry up for a quick look?'' The Doctor asked, ''everything seems alright down here but I'm detecting a little something from upstairs, just need to make sure there isn't a potential leak.''

''Oh, I shouldn't like to disturb him at the moment…''

''It'll just take a tick- scouts honour.'' He told her, with a little wink. ''He won't even know we're there.''

''Quiet as mice!'' Donna added, already seeing the older woman's resolve start to crumble at the mild amount of charm the Doctor was laying out, giving her a reassuring touch to the arm a moment later.

''Well, I'm sure you've seen enough kitchens that theirs won't shock you! Just don't open the fridge...''

Expect the unexpected; that was a mantra that Donna had learned to keep, reminding herself from time to time in her head that anything mad that she experienced with or because of the Doctor was probably not that crazy in the grand scheme of things. The universe was an endless expansion of mystery, and she knew that better than ever nowadays.

And yet, she was still taken aback to find a sullen young man with wavy dark hair sitting in the living room, staring hard into the empty air. He didn't look up as they entered the room, barely even breathed.

''Is _that_ Sherlock Holmes?'' She breathed to the time traveller beside her, peering around the doorframe before he stepped into the room.

''Must be…bit young, very young,'' He murmured back, offering a smile as the man turned his head to regard them both levelly, ''hello!''

''Who are you and what do you want?'' He asked them, retaining his unnatural stillness.

''We're here to check your gas appliances, bit of trouble round this street, routine stuff, nothing to worry about, are you really Sherlock Holmes?''

''Yes.'' The stiff response. ''And there is nothing wrong with our gas appliances. If there was, I would have blown up the flat yesterday afternoon.''

''Ah, well, better safe than sorry, won't be a minute.'' The Doctor replied, striding forward and taking in the room; black and white floral wallpaper, a madness and mess which he knew had method to it, a young man staring at him hard in a plain black suit. As if to appease him, the Doctor took out his sonic screwdriver, flicked it to the setting he wanted and tossed it backwards to Donna, who clutched it to her chest in a fumbled but successful catch.

She opened her mouth, ready to go full stream, but a look from the Doctor gave her cause to restrain herself. Instead she raised her eyebrows, giving him a warning look, and went along to check the kitchen.

''I'll leave the fridge alone, shall I?'' She asked sweetly, looming in close to the Gallifreyan. He flinched, only half playfully, glancing back to Sherlock Holmes who had risen from his chair.

''You aren't here to do any gas check,'' he told them both matter of factly, ''neither of you are in uniform, and while women do occasionally work in such a profession, it's rather unlikely, especially a woman such as you.''

''Beg your pardon?''

''Donna.'' The Doctor warned, hearing the tone in her voice as she turned to look at them both- but both Donna and Sherlock ignored him.

''Hair down, unprofessional for travelling door to door checking gas meters and appliances, full make up, slightly smudged, applied during travel, inappropriate footwear, trousers neat but not intended, again, for working from house to house-''

''Blimey, you get right into it don't you?'' The Doctor noted with a helpless grin, pulling out the psychic paper again and brandishing it at the younger man. ''Here's my identification-''

''And where is hers?'' Sherlock demanded, snatching the ID and giving her a sceptical look.

''Left it in the van.'' She responded airily, jerking the screwdriver in the direction of the house front.

''There isn't a van, there's nothing outside.''

''It's around the corner.''

''John Smith? Really?'' Sherlock scowled at the ID, looking up at the man who had handed it over, ''this is _obviously_ a forged ID card-''

''Oop, hold on, hold on-'' The Doctor recognised the little pull of the screwdriver, the sound it made when it caught a trace of what he'd set it to find; he yanked it away from Donna and, with a quick little turn, yanked back the ID from Sherlock as well. ''Mind if I have a peek over here? Detecting something off-''

''There's nothing over there for you to check, you're both lying and I want you to get out. _Mrs Hudson_!''

''What exactly is in the fridge then? Can't be any worse than Sandra's boyfrie-_ohmygod_!'' Donna slammed the fridge door shut a second after opening it, stepping backwards and staring at Sherlock. ''There's a head in the fridge!''

''Where've you gone, come on now…'' The Doctor murmured, waving the sonic back and forth until he picked up on the trace again. He was drawn to a wastepaper basket near the fireplace, frowning lightly.

''There is a head- in the fridge- _why_ is there a head in the bloody fridge!?''

''It's research. Are you going to tell me who you are or do I need to call the police?''

''Mmn….just a trace…this isn't the right place. This isn't the right _time_…'' The Doctor continued, oblivious now to either of the others in the flat. He reached into the bin, pulling out a neat little silver pen knife, lodged hard into an apple. He turned it, seeing large letters carved into the fruit, the flesh having turned a little brown, the skin curling around the letter edges.

''I. O. U?''

A hand on his collar suddenly caught the Doctors attention, finding himself hauled to his feet and pulled away from the bin.

''_Get out_. I know who you are, both of you.''

''What?''

''He's got a head in the fridge, he's _mental_!''

''What is it, whatever's the matter?'' Mrs Hudson bustled in from the landing, looking bewildered as the visitors edged towards her and the doorway. ''Oh, dear, did you look in the fridge? You really shouldn't keep those things in there, Sherlock…''

''These people are not who they say they are, Mrs Hudson, phone the police.'' Sherlock informed her, ''they're snooping, they're here to get information.''

''Oh, but, he fixed the washing machine while he was downstairs…''

''Mrs Hudson!''

''Nothing wrong up here Mrs Hudson, everything's clean! We'll send you a letter. Bye!'' The Doctor said, taking her hand and squeezing it reassuringly as Donna hurried towards the stairs. With a last look at Sherlock Holmes, the Doctor departed, hurrying down the stairs after Donna and out onto the street, letting the door fall closed behind him.

''Sherlock, whatever's the matter?''

Already at the window, Sherlock watched them go, running down Baker Street and around the nearest corner. His pale green eyes narrowed, mouth tensed and dry. He had been trying to drive that out of his mind for hours, on the verge of throwing the contents of the bin out of the window.

He had not needed them spoken aloud by some stranger with a flashlight pen and a fake ID.

_I. O. U._


	3. Miscalculation

AN- Thanks to those of you who have started following this fic, hope you enjoy the next chapter!

* * *

''I don't understand, who do you think they were?''

Mrs Hudson stood patiently by the door, having heard it slam- though not as violently as it sometimes did when the consulting detective slid out at all hours of the day and night. He was rigid as he stood at the window, watchful long after the strange pair had vanished. He had been the same when Mrs Hudson got home, offering him a cup of tea, asking if he knew how the trial had ended.

He told her he'd already had some and to go away.

''Isn't it obvious?'' He replied, still staring through the glass. A flicker of black caught his eye as a cab pulled up; John, still in his smart suit and badly chosen striped tie, though now it was stuffed into his jacket pocket. It fluttered as he strode towards the front door.

''Well, _everything_ is obvious to you, Sherlock...''

''They were _fans_.'' He responded, finally turning away from the window with one swift motion. A quick 180 as he turned to face her, wearing an expression of deep distaste. Even the word was repellent in his mouth.

''Fans?'' The woman couldn't help chuckling, going to inspect the china that had been laid out when she first checked in on him. Still bearing remnants of tea; she should have come for it when she was doing the other washing up. ''How do you know that?''

''Oh, come on, just look at them- a duo, pretending to investigate something, one more intelligent than the other, fake ID, long coat-''

''His collar wasn't turned up, dear.''

''I don't do that.'' Sherlock retorted, striding across to his armchair and letting himself fall into it as John Watson entered the room.

''Don't do what? Answer your phone? Because you don't do that every time either.''

''I heard all I needed to.''

''Sherlock-'' John paused, steeling himself, his fingers alighting on the tie in his pocket as his hands went to rest on his hips, ''I'm just as angry as you are. It's all a scam-''

''Of course it is.''

''But there's nothing we can do now, other than watch him close. He's been in all the papers, they know his name, his face…''

''Yes, yes, and then the game begins again, doesn't it, it all goes round again because that's how he works.'' Sherlock muttered, long legs stretched out in front of him as he slouched in the chair. He had waited until every trace of Moriarty's heat had evaporated out of the fibres before he returned to it.

''No. No, you'll stop him.'' John said firmly, shaking his head, and then his tone softened; reassurance and faith. ''You'll stop him, Sherlock.''

''Yes.'' Sherlock replied after a moment. He stared ahead, into the void, into a nothingness which was invisible to those who shared the room with him. A gentle clink of china as Mrs Hudson collected the cups. His head turned, gaze resting on John Watson who stood resolute, angry, but not at him.

For him.

Sherlock offered a twitch of a smile, though it didn't register in his eyes.

''Yes. I will, John.''

* * *

''_That _was Sherlock Holmes? Are you kidding me?'' Donna asked, shrugging off her jacket as they entered the TARDIS. ''I thought he was older, and his nose didn't look how I thought it would, and did you see his hair? What a scruff!''

''Yeeeah, well, Holmes was a bit of a scruff in the stories, I mean- he dressed like a gentleman but he kept his tobacco in a slipper and all sorts- but, I did pick up on something though, enough to know the trace had been there- but we missed it.''

''Missed it?''

''I think we overshot,'' the Doctor explained, jamming the sonic screwdriver into a port and examining the data it had collected on the screen, ''whatever or whoever caused the glitch, it wasn't here and now, even though their presence was left behind in that room. When we got pulled in, we were in turbulence. As soon as I tried to land the TARDIS…aha! When I tried to steady us and bring the ship down we overshot where the glitch actually is _in time_. Only a few years, I think, three or four.''

''Oh, yeah, only three or four, s'like five minutes.'' Donna replied, smirking a little as the Doctor gave her a look.

''Yeah alright,'' he couldn't help a little grin, ''you try landing this thing precisely after a burst of turbulence like that. It's not like parking a car...''

''That's a point, y'know. Did you have to have a test for this thing? Aww, did you have to have lessons?''

''Yeah, I had a little 'L' plate and everything.'' He replied wryly, earning a laugh from the red headed woman before grabbing hold of a nearby lever, ''right, come on then! Let's get to the glitch site and see if we can work out what Mr Holmes has to do with it.''

''Oh, here it comes….'' Donna rolled her eyes, but she was still grinning as she grabbed hold of something ready for the flight.

He yanked down on the lever and the TARDIS began to vibrate, that familiar, indescribable sound seeping through the air from the very heart of the machine, passing through them both, around them, and through the fabric of time and space itself.

''Allonsy!''


End file.
